Now, people don't usually think of minions as being that important, but can you imagine LoL without them? They're invaluable so why not have a champion that specializes with minions. With the wars in the lore, it wouldn't be surprising to have a general like Swain. The gimmick for this character is that his abilities work with minions.
Passive: Inspire, ally minions do more an take less damage.
Q: Rank Up, Make a minion more powerful.
W: Bodyguard, passive: Any single target attack that hits you will do damage to a nearby enemy instead. Active: Escort, summon an escort to fight with you a while.
E: Target, Active: If used on an ally (Champion, tower, or minion), all enemy towers and minions will target it. If used on an enemy, all ally towers and minions will target it. Passive: Basic attacking an enemy marks it so it takes more damage from minions.
R: Recruit, Active: Instantly creates a new wave of minions. Passive: Every wave while this champion is in play spawns a ghost minion as well (Basically a regular minion but doesn't give gold when killed).
This skill set works well for laning, but not so much for team fighting. More of a power laner he can put major pressure on a lane. With Rank up he can make a minion stronger, much like Banner of Command. Bodyguard is your best defensive skill because it protects you from single target attacks (But not AoE) and offensive working a bit like Anne's summon. Target is most useful around turrets because you can have the turret focus on an attack champion, or redirect it from an ally who tower dived. It's passive gives you a reason to basic attack enemies rather than just hide behind your army. Finally the ult puts major pressure on your enemy from all lanes rather than just yours with both the active and passive. More of a support class I think, he might make an interesting champion.